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@uitrit tats jatmt @ft-ire Lettere'latcnt' No. 7 5,234-, dated' Illm'ch 10, 1868.

IMPROVEMENT IN BOAT-DETAGHING BLOCKS.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I, NELSON B. ADAMS, of the city and county of San Francisco, State of California, have invented an Improved Bleek and Ivoat-Detachingvr Apparatus; and I do hereby declare thc following description and accompanying drawings aresuiieient' to 'enable any person skilled in the art or science to which it most nearly appertains to make and use my said invention or improvements without further invention or experiment.

My invention relates to that class of mechanism known as beat-detaehinfz,- apparatus; audit consists, first, in au improved device for detaching, and, secondly, in so combining it with the block as to make it applicable to any apparatus in which it is. necessary to detach promptly. To more fully explain my invention, reference is made to the accompanying drawings, forming a part of this specification, of whichl Figure 1 is a side sectional view taken through x fr, g.i2.

Figure 2 is an elevation, showing an e-nd view of the levers.

Similar letters of reference, in each ofthe figures, indicate like parts.

A A are the sides of the block, and I3 B are two plates placed between the sides, at Ysuch a-distanee that the pulleys C C turn between A and .Il The detaching-apparatus is placed between the plates BB, and consists of two bent levers hinged together at D. The short arms E E form the jaws, by shutting firmly together.` The-long arms F F have hinged to them at G G the two short levers II II, which moet and are hinged at the` top atiI, thus forming a knee-lever, which, when operated, acts with increasing force to separate the long arms F F, and thus close the jaws E E. rIhe two levers II II have shoulders a a, formed at the top of the hinge, so that when the jaws E are closed, and these levers are in a straight or nearly straight line, they can be moved no farther downward, being prevented by the shoulders ,ft-a. 'Ihesc shoulders arer so placed that the levers II I-I pass a little below a straight line, so that any pressure will tend to hold them more firmly in plaee. A lever, J, has its fulcrum at G', and is pivoted at I in a line with one ofthe levers H, and serves to operate the mechanism. i

'Iwo blocus being used, one at each end of the boat, the lever J may either be operated at the word of command, by two men, or they may be so connected as to be moved by one, and thus detach both ends of the boat simultaneously.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

In combination with a block, the jaws E E, with the long,r arms F F, the short levers II II, with shoulders a a, forming aknce-joint, the operating-lever J, having its fulcrum at G, and pivoted to the knee-joint I, the whole constructed, combined, and operating as a dewishing-apparatus, substantially as and for the purposes herein described.

In witness whereof, I have hereunto set my hand and seal.

' NELSON I3. ADAMS' [L. s]

Witnesses:

JNO. L. BOONE, GEO. H. STRONG. 

